title: Inversion of helix orientation in Bacillus subtilis macrofibers.
abstract: The ability of helical macrofibers of Bacillus subtilis to convert from left- to right-handed structures or vice versa has been known to be controlled by the nutritional environment (N. H. Mendelson, Proc. Natl. Acad. Sci. U.S.A., 75:2478-2482, 1978). lyt mutants (Ni15, FJ3, FJ6, and FJ7) and also lyt phenocopies of wild-type strain FJ8 were able to undergo helix hand inversion as a function of temperature. The transition between right- and left-handed structures was in a very narrow range (about 2.5 degrees C) in the low to mid-40 degrees C. The helix orientation of these strains was also influenced by the concentration of divalent ions. Macrofiber handedness is governed, therefore, by at least four factors: genetic composition, temperature, and nutritional and ionic environments. Conditions normally used for growth fall, within this matrix, in the region favoring right-handed structures. Inhibition studies suggest that cell growth must occur for helix hand inversion.
mesh_terms: D001412:Bacillus subtilis / Q000166:cytology* / Q000235:genetics; D002413:Cations, Divalent; D003470:Culture Media; D005838:Genotype; D009154:Mutation; D013696:Temperature
chemical_list: D002413:Cations, Divalent; D003470:Culture Media